US3773366A — Antiskid device for car wheels especially for roa…

Claim 1

Independent Claim 377 words

Anti-skid apparatus for a vehicle wheel comprising: a. brake applying means operable responsively to fluid pressure for applying a braking force to the wheel commensurate with the degree of fluid pressure supplied thereto; b. fluid pressure supply means including a source of fluid under pressure and an operator''s brake valve device selectively operable to a plurality of supply positions for effecting supply of fluid pressure from said source to said brake applying means at a measured pressure determined by the position to which the operator''s brake valve device is operated for causing deceleration of the wheel at a rate normally commensurate with said measured pressure; c. braking pressure control means interposed between said brake applying means and said fluid pressure supply means and having a normal position in which unrestricted flow of fluid pressure supply to the brake applying means, at said measured pressure, is effected, said braking pressure control means being operable to a different position in which interruption of braking pressure supply to the brake applying means and reduction of such braking pressure therefrom to atmosphere is effected; and d. wheel slip detector means operable responsively to wheel deceleration at a certain rate, at which the skid threshold of the wheel is reached, to a first disposition for effecting operation of said braking pressure control means to its said different position, and being operable responsively to restoration of wheel deceleration to a rate compatible with that of linear deceleration of the vehicle to a second disposition for effecting restoration of said braking pressure control means to its said normal position; wherein the improvement comprises: e. a throttle piston disposed in said braking pressure control means in the flow path of fluid pressure supplied to the brake applying means, said throttle piston having an open position in which said unrestricted flow of pressure supply is effected and being operable, by initial movement of the braking pressure control means from its said different position toward its said normal position, to a throttling position in which said reduction of braking pressure from the brake applying means is terminated, and restoration of the braking pressure control means to its said normal position and, consequently, restoration of braking pressure to said measured pressure is delayed according to a predetermined rate.

Claim 2

Dependent Claim 377 words

Anti-skid apparatus for a vehicle wheel comprising: a. brake applying means operable responsively to fluid pressure for applying a braking force to the wheel commensurate with the degree of fluid pressure supplied thereto; b. fluid pressure supply means including a source of fluid under pressure and an operator''s brake valve device selectively operable to a plurality of supply positions for effecting supply of fluid pressure from said source to said brake applying means at a measured pressure determined by the position to which the operator''s brake valve device is operated for causing deceleration of the wheel at a rate normally commensurate with said measured pressure; c. braking pressure control means interposed between said brake applying means and said fluid pressure supply means and having a normal position in which unrestricted flow of fluid pressure supply to the brake applying means, at said measured pressure, is effected, said braking pressure control means being operable to a different position in which interruption of braking pressure supply to the brake applying means and reduction of such braking pressure therefrom to atmosphere is effected; and d. wheel slip detector means operable responsively to wheel deceleration at a certain rate, at which the skid threshold of the wheel is reached, to a first disposition for effecting operation of said braking pressure control means to its said different position, and being operable responsively to restoration of wheel deceleration to a rate compatible with that of linear deceleration of the vehicle to a second disposition for effecting restoration of said braking pressure control means to its said normal position; wherein the improvement comprises: e. a throttle piston disposed in said braking pressure control means in the flow path of fluid pressure supplied to the brake applying means, said throttle piston having an open position in which said unrestricted flow of pressure supply is effected and being operable, by initial movement of the braking pressure control means from its said different position toward its said normal position, to a throttling position in which said reduction of braking pressure from the brake applying means is terminated, and restoration of the braking pressure control means to its said normal position and, consequently, restoration of braking pressure to said measured pressure is delayed according to a predetermined rate.

Claim 3

Dependent Claim 40 words

Anti-skid apparatus, as set forth in claim 1, wherein said throttle piston assumes a cut-off position in the said different position of the braking pressure control means for effecting said interruption of braking pressure supply to the brake applying means.

Claim 4

Dependent Claim 75 words

Anti-skid apparatus for a vehicle wheel, as set forth in claim 1, wherein said wheel slip detector means is also operable, subsequently to operation of said braking pressure control means to its said different position and responsively to consequent restoration of wheel rotation to a rate below that corresponding to the wheel skid threshold, to a third disposition for effecting operation of the braking pressure control means and said throttle piston to the throttling position.

Claim 5

Dependent Claim 66 words

Anti-skid apparatus, as set forth in claim 3, wherein the braking pressure control means comprises: a. differential piston means; and b. valve means operable responsively to operation of said wheel slip detector means to its said first, second, and third dispositions to cause operation of said differential piston means for effecting operation of the braking pressure control means to said different, normal, and throttling positions, respectively.

Claim 6

Dependent Claim 31 words

Anti-skid apparatus, as set forth in claim 4, wherein the wheel slip detector means comprises an electrical wheel slip detector device and said valve means comprises electrically operable magnet valve means.

Claim 7

Dependent Claim 297 words

Anti-skid apparatus, as set forth in claim 3, wherein said braking pressure control means comprises a valve assembly including: a. a valve stem; b. a first operating piston fixed at one end of said valve stem and subjectable to fluid pressure from said source by operation of said wheel slip detector means to its said first disposition for operating the braking pressure control means to its said different position; c. a second operating piston having a larger pressure area than said first operating piston and carried at the opposite end of said valve stem in operably opposing relation to said first operating piston and with limited axial movement relative to the valve stem, said second operating piston being subjectable to fluid pressure from said source, by operation of said wheel slip detector means to its said third disposition, and being operable responsively to said fluid pressure for overcoming opposing fluid pressure acting on said first operating piston and effecting operation of the valve assembly and said throttle piston to said throttling position; and d. a vent valve member fixed on said valve stem in sucH an axial position as to occupy a closed position, in which communication between said brake applying means and atmosphere is cut off, in both the normal and throttling positions of the braking pressure control means, and an open position in which said communication is open in the different position of the braking pressure control means; e. said throttle piston being carried on said valve stem adjacent said first operating piston and having limited axial movement relative to the valve stem for effecting said interruption and for throttling said supply of fluid pressure to the brake applying means in the different position and the throttling position, respectively, of the braking pressure control means.

Claim 8

Dependent Claim 20 words

Anti-skid apparatus, as set forth in claim 6, wherein said first and second operating pistons are of the diaphragm type.

Claim 9

Dependent Claim 123 words

Anti-skid apparatus, as set forth in claim 6, wherein said valve assembly further comprises: a. first biasing means acting on said first operating piston through said throttle piston in opposition to the fluid pressure acting on said first operating piston; and b. second biasing means acting on said second operating piston in opposition to the fluid pressure acting thereon, said first and second biasing means being of such calibration and acting cooperatively with the opposing fluid pressures acting on the respective operating pistons as to maintain said valve assembly and the throttle piston in said throttling position until said measured pressure has been restored in the brake applying means and the braking pressure control means has been restored to its said normal position.

Claim 10

Dependent Claim 272 words

Anti-skid apparatus, as set forth in claim 2, wherein said braking pressure control means comprises: a. a valve stem having said throttle piston mounted at one end thereof with limited axial movement relative thereto; b. compressible biasing means for urging said throttle piston to an open position against said one end of the valve stem and in which said unrestricted flow of fluid pressure supply to the brake applying means is effected; and c. a diaphragm type operating piston fixed to the opposite end of said valve stem, normally subjectable to equal fluid pressures on opposite sides thereof, and being operable by said biasing means, acting through said throttle piston and said valve stem, to a supply position for effecting operation of the braking pressure control means to its said normal position, said operating piston being operable, responsively to reduction of fluid pressure from one side thereof by said wheel slip detector means in its said first disposition, to a venting position for effecting operation of the braking pressure control means to its said different position in which said throttle piston initially assumes its said throttling position, d. said throttle piston, in said throttling position, being subject to a pressure differential established thereacross by fluid at said measured pressure acting on one side thereof and pressure prevailing in said brake applying means acting on the opposite side thereof, subsequently to operation of the braking pressure control means to its said different position, said pressure differential being effective for maintaining said throttle piston in its said throttling position until pressure acting on the opposite side thereof has been restored to said measured pressure.

Claim 11

Dependent Claim 270 words

Anti-skid apparatus, as set forth in claim 2, wherein said braking pressure control means comprises: a. a control valve device including biasing means for operating said control valve device to a supply position, in which fluid pressure supply to the brake applying means is effected, and being operable, responsively to operation of said wheel slip detector means to its said first disposition, to a venting position in which said interruption of braking pressure supply to and reduction thereof from the brake applying means is effected; an operating piston fixed at one end of a valve stem and having one side thereof subjectable to fluid pressure by operation of the wheel slip detector means to its said first disposition and relieved of such pressure in the second disposition of said wheel slip detector means, the other end of said valve stem making abutting contact with one side of said throttle piston; first biasing means acting on the opposite side of said operating piston for biasing said throttle piston, through the operating piston and the valve stem, to its said open position; and d. second biasing means acting on the opposite side of said throttle piston and effective upon pressurization of said one side of the operating piston and consequent neutralization of the biasing effect of said first biasing means, for operating the throttle piston to its said throttling position, e. said throttle piston being restorable to its said open position by said first biasing means and said control valve device being restorable to its said supply position responsively to operation of the wheel slip detector means to its said second disposition.

Claim 12

Dependent Claim 232 words

Anti-skid apparatus, as set forth in claim 2, wherein said braking pressure control means comprises: a. a control valve device normally occupying a supply position in which said unrestricted flow of fluid pressure supply to the brake applying means is effected, and being operable, responsively to operation of said wheel slip detector means to its said first disposition, to a venting position in which said interruption of braking pressure to and reduction thereof from the brake applying means is effected; and b. biasing means acting on one side of said throttle piston for urging the throttle piston toward its said open position, said throttle piston being subject on the opposite side to fluid at said measured pressure and on said one side to the fluid pressure prevailing in the brake applying means, c. said throttle piston being operable to its said throttling position responsively to reduction of fluid pressure acting on said one side as effected by operation of said control valve device to its said venting position and being subject, in said throttling position, to a pressure differential thereacross established by the respective fluid pressures acting on the opposite sides of the throttle piston, said pressure differential being effective for delaying restoration of braking pressure in the brake applying means to said measured pressure for a predetermined period subsequently to restoration of said control valve device to its said supply position.

Annuity Stage	Window Opens	Payment Deadline	Surcharge Period Until	Estimated Fee	Status
3.5 Years (Year 4)	1976-11-19	1977-05-21	1977-11-20	$2000.00	Window Closed / Lapsed
7.5 Years (Year 8)	1980-11-19	1981-05-21	1981-11-20	$3760.00	Window Closed / Lapsed
11.5 Years (Year 12)	1984-11-19	1985-05-21	1985-11-20	$7700.00	Window Closed / Lapsed

Antiskid device for car wheels especially for road vehicles

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